1. Technical Field
The present disclosure relates to a woven fabric having filaments with a pentagram cross-section, and more particularly, to a woven fabric having filaments with five projections and recesses to retain low air permeability after repeated washing.
2. Description of Related Arts
The woven fabric used for the outside surface or inside surface of a garment, such as a down jacket or a fake down jacket, is required to have a low air permeability to ensure that the down or the fake down in the garment can be prevented from coming out and that the garment can be deformed to be inflated and deflated in response to the air coming in and out. In order to achieve low air permeability, the conventional techniques are methods of enhancing the weave density of the fabric and calendering the fabric, to compress the filaments, for lessening the inter-yarn gap; for example, the method disclosed in US 2011/0302689.
However, there are fundamental problems with the conventional methods of controlling low air permeability by enhancing the weave density and calendering in that the ability to easily undergo the process is unreliable since yarn breaking may frequently occur and the productivity remains minimal since the weaving speed is relatively slow. Furthermore, even if the woven fabric that is obtained has a low air permeability at the initial state, it is very difficult to maintain the initial low air permeability since the inter-yarn gap is spread out during lapses of time by such forces as bending and expansion/contraction in the daily uses associated with folding, washing, etc. Consequently, down or fake down is likely to dissipate.